• 제목/요약/키워드: Kinematic factors

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Three-dimensional kinematic motion analysis of door handling task in people with mild and moderate stroke

  • Lee, Jung Ah;Kim, Eun Joo;Hwang, Pil Woo;Park, Han Ram;Bae, Jae Hyuk;Kim, Jae Nam
    • Physical Therapy Rehabilitation Science
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    • 제5권3호
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    • pp.143-148
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    • 2016
  • Objective: This study aimed to quantify one of the useful upper extremity movements to evaluate motor control abilities between the groups of people with mild and moderate arm impairments performing a door handling task. Design: Cross-sectional study. Methods: Twenty-one healthy participants and twenty-one persons with chronic stroke (9 mild stroke and 12 moderate stroke) were recruited for this study. Stroke participants were divided into 2 groups based on Fugle-Meyer Assessment scores of 58-65 (mild arm) and 38-57 (moderate arm). All they performed door handling task including the pronation and supination phases 3 times. We measured some movement factors which were reaction time, movement time, hand of peak velocity, hand of movement units to perform door handling task using the three-dimensional motion analysis. Results: The majority of kinematic variables showed significant differences among study groups (p<0.05). The reaction time, total and phase of movement time, hand of peak velocity, the number of movement units discriminated between healthy participants and persons with moderate upper limb stroke (p<0.05). In addition, reaction time, total and phase of movement time, the number of movement units discriminated between those with moderate and mild upper limbs of stroke patients (p<0.05). Conclusions: Three-dimensional kinematic motion analysis in this study was a useful tool for assessing the upper extremity function in different subgroups of people with stroke during the door handling task. These kinematic variables may help clinicians understand the arm movements in door handling task and consist of discriminative therapeutic interventions for stroke patients on upper extremity rehabilitation.

골프의 짧은 어프로치 동작 시 타구의 정확성에 영향을 미치는 운동학적 변인 분석 (Kinematic Factors Influencing on the Precision of Short Approach Shoots in Golf)

  • 김호묵;우상연;정승은
    • 한국운동역학회지
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    • 제17권2호
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    • pp.227-237
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    • 2007
  • The purpose of this study was to examine the effect of precision that kinematics had when short approach shots were taken. In this study, the subjects chosen were 5 skilled and 5 unskilled subjects, who were allowed to shoot 10 rounds of shots at target distances of 1m, 2m, 4m, and 8m. Three dimensional analysis was used as methods to obtain kinematics of each shots. In order to verify the statistical significance of the kinematic factors followed by the results of different skills and target distances, we used the two-way repeated ANOVA. The study was experimented within the level of p<.05. The results obtained were as follows: 1) the difference of shots of the forward and backward variations were larger than those of the left and right variations, the unskilled subjects' shot distances greatly got larger than that of the skilled subjects as the distance of the target increased, 2) not being affected by the target distance variations, the skilled subjects' rate of down-swing was shorter than the back-swing on short approach shots, 3) the skilled subjects' center of body weight tended to move more naturally towards the target when doing the down-swing to finish than that of the unskilled subjects on short approach shots, 4) the skilled subjects' right hand angle of cocking were narrower and tended to be kept much more consistent than that of the unskilled subjects on short approach shots, 5) the unskilled subjects when doing their back-swings, their right hips swayed towards the back, their trunk-flexion angles were shown to be lower than that of the skilled subjects on short approach shots, 6) the skilled subjects`body weight tended to move more naturally towards the left foot when doing the down-swing to finish than that of the unskilled subjects on short approach shots.

점탄성층을 갖는 복합재보의 축하중 작용시 진동해석 (Vibration Analysis of Axially-Stressed Composite Beam with Viscoelastic Layer)

  • 이덕규
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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    • pp.33-38
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    • 2002
  • Dynamic analysis of laminated beams with a embedded damping layer under tension or compression axial load is investigated. Layer-Wise Zig-Zag Beam Theory and Interdependent Kinematic Relation using the governing equations of motion are incorporated to model the laminated beams with a damping layer and a corresponding beam zig-zag finite element is developed. Flexural frequencies and modal loss factors under tension or compression axial load are calculated based on Complex Eigenvalue Method. The effects of the axial tension and compression load on the frequencies and loss factors are discussed.

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사판식 피스톤 펌프의 밸브 플레이트 설계와 예압에 따른 맥동 (Pulsation According to Pre-Compression Sections and Valve Plate Design for a Swash Plate Type Piston Pump)

  • 사진웅;정원지;배준형;이정민
    • 한국생산제조학회지
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    • 제25권1호
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    • pp.89-95
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    • 2016
  • This study investigated the design factors of the opening area in order to consider the kinematic stability of a valve plate, conducting an analysis of the reduction effects of pressure pulsation and flow ripple depending on the design factors, using the $SimulationX^{(R)}$ (Germany) hydraulic analysis program. Further, we performed a structure analysis to confirm the kinematic stability of the valve plate in a swash plate type piston pump, and analyzed the effects of pulsation on a 1-step V-type notch, 2-step V-type notch, and 2-step U-type notch to determine the effects of pulsation reduction. Finally, we show the effectiveness of our proposed design of the pre-compression sections on a valve plate in terms of low pulsation by using the hydraulic analysis program, $SimulationX^{(R)}$.

임신 기간에 따른 임산부 보행의 운동학적 요인과 하지 관절모멘트 패턴 비료 (Comparison of Gait Patterns on Pregnant's Kinematic Factors and Lower-Limb Joint Moments During Pregnant Period)

  • 하종규;장영관
    • 산업경영시스템학회지
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    • 제32권3호
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    • pp.78-84
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    • 2009
  • The purpose of this study was to compare gait patterns during pregnancy. Because of the changes in hormone levels and anatomical changes such as body mass, body-mass distribution, joint laxity, and musculotendinous strength that result from pregnancy, it was possible that there would be certain gait deviations associated with these changes. Three-dimensional gait analyses were performed from a self-selected pace, and six subjects(height : $163{\pm}5.3cm$, mass : $61.3{\pm}3.80kg$, $65.3{\pm}5.14kg$, $70.2{\pm}4.98kg$) participated in the three times(the early, middle and last years). 7 cameras(Proreflex MCU-240, Qualisys) and 2 force plates (Type 9286AA, Kistler) were used to acquire raw data. The parameters were calculated and analyzed with Visual-3D and Joint moments computed using inverse dynamics. In conclusion, pregnant women's gait patterns were changed during pregnancy period because pregnancy makes them physical changes. The main changes were joint moments and kinematic factors during pregnancy period. The pregnancy transformed normal gait pattern Into toe out position. Therefore, exercise programs to improve muscle activity were necessary where joint moments were small. The development of simulator should be studied for pregnant women's tailored shoes and accessories in future.

스윙 암 컨디셔너의 기구학적 해석을 통한 CMP 패드 프로파일 변화에 관한 연구 (A Study on Pad Profile Variation using Kinematical Analysis on Swing Arm Conditioner)

  • 오지헌;이상직;이호준;조한철;이현섭;김형재;정해도
    • 한국전기전자재료학회논문지
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    • 제21권11호
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    • pp.963-967
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    • 2008
  • There are many factors to affect polishing performance normally in chemical mechanical polishing (CMP) process. One of the factors is a pad profile. A pad profile has not been considered as a significant factor. However, a pad profile is easily changed by conditioning process in CMP, and then changed pad profile affects polishing performance. Therefore, understanding how the pad profile is changed by conditioning process is very important. In this paper, through the simulation based on kinematic analysis, the variation of the pad profile was described in accordance with difference condition of conditioning process. A swing-arm type conditioner was applied in this simulation. A swing-arm type conditioner plays a role of generating asperities on pad surface. The conditions of conditioing process to get uniform removal were also investigated by comparing the simulation with the experiment.

엄지발가락가쪽휨증의 엄지벌림근 전기자극 시 첫 번째 발허리발가락관절의 운동형상학적 움직임 분석 (Analysis of Kinematic Motions of First Metatarsophalangeal Joint during Electrical Stimulation of Abductor Hallucis Muscle in Subjects with Hallux Valgus)

  • 김문환;고은경;정도영
    • The Journal of Korean Physical Therapy
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    • 제24권4호
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    • pp.276-281
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    • 2012
  • Purpose: The purpose of this study is to compare the kinematic motion of the first metatarsophalangeal (MTP) joint during an electrical stimulation of abductor hallucis (AbdH) muscle, between the normal group and the hallux valgus (HV) group. Methods: A total of twenty subjects (normal group=10 and HV group=10) participated in this study. The kinematic motions of first MTP joint was measured by using 3-dimensional motion analysis during an electrical stimulation in the sitting position. The intensity of an electrical stimulation was set to be tolerated in each subject, and the data of kinematic motions were collected in three trials of 5 seconds. An independent t-test was used to compare the angle of flexion and abduction of the first MTP joint and proximal phalanx in frontal plane, between the normal and HV groups. Results: Participants showed that the angle of flexion was significantly greater in the HV group ($13.12{\pm}10.61^{\circ}$), compared to that of the normal group ($10.17{\pm}2.31^{\circ}$); and the angle of abduction was significantly smaller in the HV group ($10.61{\pm}4.99^{\circ}$) than that of the normal group. Also, the angle of the proximal phalanx in frontal plane was significantly smaller, compared to the normal group ($53.42{\pm}10.70^{\circ}$) (p<0.05). Conclusion: These findings suggest that dysfunction of AbdH muscle is apparent in HV deformity and provide insight into potential risk factors for the development of HV deformity.

공작기계용 접촉식 측정 프로브의 프로빙 오차 보상에 관한 연구 (Touch-Trigger Probe Error Compensation in a Machining Center)

  • 이찬호;이응석
    • 대한기계학회논문집A
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    • 제35권6호
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    • pp.661-667
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    • 2011
  • 접촉식 측정 프로브는 3 차원 좌표 측정기 및 CNC 공작기계 등에서 제품 검사에 많이 활용되고 있고, 최근 품질 향상을 위한 가공 및 검사장비의 고정도화에 따라 측정의 정확도도 또한 매우 중요시 되고 있다. 이에 따라 스트레인 게이지 등을 이용한 고정도의 측정 프로브가 사용되고 있기는 하지만, 본 연구에서는 경제적인 측면을 고려하여 산업현장에서 공작기계에 많이 활용되는 일반 접촉식 측정 프로브의 메커니즘을 이해하고, 측정 시 발생할 수 있는 프로빙 오차에 대한 분석 및 보정을 통하여 그 활용성을 높이고자 하였다. 이를 위하여 스타일러스 반경 및 중심 정렬오차가 규명되었고, 3 차원 공간상의 측정 좌표에서 프로빙 오차에 대한 해석이 이루어졌다. 이러한 오차들을 보정하기 위한 알고리즘이 개발되었으며, 실제 CNC 공작기계 상에서 기준구 측정을 통한 검증이 이루어졌다.

항공기 동적 부분품에 대한 신뢰성 평가 (A Study on Reliability Assessment of Aircraft Structural Parts)

  • 김은정;원준호;최주호;김태곤
    • 한국항공운항학회지
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    • 제18권4호
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    • pp.38-43
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    • 2010
  • A continuing challenge in the aviation industry is how to safely keep aircraft in service longer with limited maintenance budgets. Therefore, all the advanced countries in aircraft technologies put great efforts in prediction of failure rate in parts and system, but in the domestic aircraft industry is lack of theoretical and experimental research. Prediction of failure rate provides a rational basis for design decisions such as the choice of part quality levels and derating factors to be applied. For these reasons, analytic prediction of failure rate is essential process in developing aircraft structure. In this paper, a procedure for prediction of failure rate for aircraft structural parts is presented. Cargo door kinematic parts are taken to illustrate the process, in which the failure rate for Hook part is computed by using Monte Carlo Simulation along with Response Surface Model, and system failure rate is obtained afterwards.

조건수를 이용한 6자유도 F/T센서의 최적구조에 관한 연구 (A Study on the optimal structure of 6 D.O.F F/T Sensor using the condition number)

  • 장완식;김재명
    • 한국안전학회지
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    • 제11권4호
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    • pp.16-23
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    • 1996
  • In controlling manipulators interacting with the external environment, an important role is played by the Force/Torque(F/T) sensors. Recently, a number of structures for F/T sensors have been proposed, and some criteria for their evaluation have been introduced. This paper presents a systematic analysis of F/T sensor at the design stage. A model of the F/T sensors, based on Stewart Platform structure, is developed on the basis of static and kinematic equation. The condition number defined by the kinematic velocity and force analysis of F/T sensor is used as a performance Index. Thus, 4 optimal structure factors of 6 D.O. F. F/T sensor are determined by using the condition number.

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